Haberstick B.C, Schmitz S., Young S.E., Hewitt J.K. (2006). Genes and developmental stability of aggressive behavior problems at home and school in a community sample of twins aged 7-12. Behavior Genetics 36(6), 809-19.

Rhee, S.H.,
Hewitt, J.K., Corley, R.P., & Stallings, M.C. (2003). The validity
of testing the etiology of comorbidity between two disorders: A review
of family studies. Journal of Child Psychology and Psychiatry, 44, 612-636.

EDUCATION

M.Sc.
Applied Genetics, September 1974.Place: Dept. of Genetics, University of Birmingham,
England.
Research Project: An analysis of data from a twin study of social attitudes.
Supervisor: L.J. EavesProfessor: J.L. Jinks

Ph.D.1978
The genetic control of activity, reactivity and learning in a natural
population of wild rats (Rattus norvegicus). Place: Institute of Psychiatry, Univ. of London.Supervisor: D.W. FulkerProfessor: H.J. Eysenck

Current Active Support (funding is annual direct costs.)

Workshop on Methodology of Twin Studies

The major goal of this project is to provide five training and information-sharing workshops for researchers involved in twin and family genetic epidemiology studies wishing to learn the latest methodology for data analysis and experimental design.

The overall goal of this Comprehensive P60 Center is to contribute to our understanding of the etiology of individual differences in behavioral control or behavioral disinhibition, the relationship of this to drug abuse and the development of dependence, and the role that these play in the propensity for risky behaviors that may result in STDs, including HIV/AIDS.

Core A: The Administrative, Educational, and Ethics Core (Hewitt)

$291,582
20% acad/1.8 acad

The major goal of the administrative and educational core is to facilitate interactions among an interdisciplinary group of clinicians, behavioral geneticists, and molecular biologists at the Health Sciences Center and Boulder Campus of the University of Colorado. The educational component supports postdoctoral training and K-12 community outreach. A unique feature of the core is the incorporation of an ethicist who will work alongside the other Center investigators. Role: PI

Core B: Data Management, Informatics and Biostatistics (McQueen)

$169,976
12% acad/1.08 acad

This Core will be responsible for the incorporation of new HIV-relevant risk and impulsiveness measures into existing interview protocols, the integration of new and previously collected data, the dissemination of consolidated data sets to Center researchers, the improvement analysis capability, and the development and application of novel statistical methods for analysis of complex phenotypes that are required to meet the specific needs of the Component Projects. Role: Co-I

Component I: Clinical and GWAS studies – Denver (Hopfer/McQueen)

$419,319
10% acad/0.90 acad

This component will identify specific genetic loci that influence behavioral disinhibition. To do this, we will conduct a genome wide association (GWAS) study on an existing sample of 1000 adolescent cases and 1000 controls with Substance Dependence, Conduct Disorder, and HIV-related risk behaviors, and a newly ascertained sample of 600 adolescents recruited from adolescent substance abuse treatment programs and a control sample of 600 adolescents without serious substance or behavioral problems. Role: Co-I

Component 2: Clinical Family and Community Twin, Family, and Adoption Studies (Stallings)

$376,234
5% acad/0.45 acad

The goal of this component is a 5-year follow-up assessment of 285 families of subjects formerly in treatment for substance use disorder (SUD) and conduct disorder (CD) as adolescents and 200 community control families. The study will provide important information regarding family influences underlying SUD & CD, the generality versus specificity of familial influences on these behaviors, and the identification of family factors that differentiate persistent versus adolescent-limited problem behavior. Role: Co-I

The National Longitudinal Study of Adolescent HealthSubcontract to Inst. for Behavioral GeneticsProject V: Gene*Environment Contributions to Drug Use and Problem Behavior Trajectories (Hewitt)

Project 4: Genetic Mechanisms of Executive Functions
The goal of this project is to use molecular genetic analyses in concert with computational modeling to begin to specify in more detail how the dopamine system regulates three correlated but separable executive functions - inhibiting prepotent response, updating working memory, and shifting mental sets. We will analyze existing molecular and psychometric data on approximately 800 individual twins who were tested on nine index executive tasks at age 17 and were also tested on general cognitive ability and IQ at age 16.

Genetics of Adolescent Antisocial Drug Dependence (COMRAD)

This COMRAD proposal continues a multisite collaboration, initiated under DA 012845, to conduct a prospective study to address critical issues in the genetic epidemiology of adolescent onset antisocial drug dependence. We will complete five year follow-up assessments, examine drug use and antisocial behavior trajectories and their predictors, and we will conduct genome wide association analyses of persistent adolescent-onset antisocial drug dependence.

Executive Functions and Self-Regulation: A Twin Study

This twin study will assess, during the transition from adolescence to young adulthood, genetic and environmental contributions to: stability and change in executive functioning: individual differences in self-regulation; and the relationships between executive functions and self-regulation.

During the years 86‑88, I was an investigator for NIH grants to study Genetic Models of Development and Aging (AG‑04954, 7/84 ‑ 6/88; Annual support $49,211), Biological and Cultural Determinants of Alcohol Consumption (AA‑06781, 8/85 ‑ 7/89; Annual support $95,168), Genetic and environmental influences on anxiety and depression (MH‑40828, 2/86 ‑ 1/90; Annual support $396,181), Resolving Power of Kinship Analysis for Genetical Research (GM‑30250, 2/86 ‑ 1/91; Annual support $75,115).

Neuropsychological investigations of abnormal interhemispheric integration and anomalous lateralization of function in children at high risk for schizophrenia. Research grant from Mental Health Foundation. 1984‑1986. Stlg 22,447.

Genetic and environmental determinants of cardiac reactivity and hypertension. Supported by project grant from the (British) Medical Research Council, 1982‑1983, jointly with Dr. Carroll (PI) and K. Last. Stlg 8,526

OTHER
SIGNIFICANT SCHOLARLY OR RESEARCH EXPERIENCE

Doctoral
and postdoctoral supervision
Genetic architecture of courtship, courtship modification, conditioning
and activity in Drosophila melanogaster.
M.F. Collins, 1980-1983, Ph.D. awarded 1983
Dr. Collins took up an SERC postdoctoral fellowship in my department
and our collaborative research in this area continued until January
1985.

Teaching
experience:

The details
of the formal courses I have taught are given below where it will be
clear that apart from my research interests in behavioral and quantitative
genetics, I have also developed teaching in statistics, measurement
and design both at the Undergraduate and Post_graduate level.

1977
-1985
Lecturer in Introductory Statistics, Psychometrics. Personality Measurement,
Research Methodology and Behavior Genetics on undergraduate courses
in the Department of Psychology, University of Birmingham.

Lecturer
in Quantitative Methods and Research Methodology on postgraduate course
in Clinical Psychology and Doctoral Programme, Department of Psychology,
University of Birmingham.

Tutor to
Introduction to Statistics for Psychology and Education, Extramural
Department, University of Birmingham, 1982.

Tutor to
Research Methods in Education and Social Science at Undergraduate and
Postgraduate Level, Open University, 1983, 1984, 1985.

1985-86
Lecturer in Behavior Genetics (course BIPY 475) and Genetics of Psychopathology
(course BIPY 399) to Biopsychology Honours Programme and Lecturer in
Research Methods (course BID 533) to Graduate Program in Biology. Department
of Biology, William Patterson College of New Jersey, U.S.A.